Dental root preparation instrument



P. BROOKS DENTAL ROOT PREPARATION INSTRUMENT Nov. 16, 1948.

2 Sheets-Sheet 1 Filed Jan. 15, 1947 3 m P71 2722795 BrooZr;

Nov. 16, 1948 P. BROOKS 5 DENTAL ROOT PREPARATION INSTRUMENT I 7 Filed Jan. 13,1947 2 Sheets-Sheet 2 P72272275 fir'ooks Patented Nov. 16, 1948 UNITED STATES PATENT OFFICE DENTAL ROOT PREPARATION INSTRUMENT Phillips Brooks, Brooklyn, N. Y.

Application January 13, 1947, Serial No. 721,737

This invention relates to dental tools and crown teeth.

An object of this invention is to provide an improved means in the form of a reamer for reaming out the canal of the root of a tooth in order to receive the shank or root of a crown tooth.

Another object of this invention is to provide an improved reamer for reaming out the canal of a tooth root and at the same time forming a base or foundation to receive the base of the crown tooth support, the reamer efiecting in a single operation the completion of the work required to receive the crown tooth which has heretofore required three or more operations.

A further object of this invention is to provide an improved reamer of tapered construction which will form the required socket for the root of the crown tooth without undue weakening of the tooth.

A further object of this invention is to provide an improved crown support which is formed with a root and a cap, and which has extending up; wardly from the cap a crownstump about which the crown tooth is secured.

A further object of this invention is to provide an improved root racer and canal enlarger which will form at the top of the root a countersunk circular foundation continuous with the enlarged root canal, and which form an annular trough below and continuous with the outer circumference of the countersunk foundation to receive a metal cap and shank support without weakening the root.

To the foregoing objects, and others which may hereinafter more fully appear, the invention consists of the novel construction, combination and arrangement of parts, as will be more specifically referred to and illustrated in the accompanying drawings, but it is to be understood that changes, variations and modifications may be resorted to which fall within the scope of the invention as claimed.

In the drawings,

Figure 1 is a detailed side elevation of a reamer constructed according to an embodiment of this invention,

Figure 2 is an enlarged longitudinal section, partly in detail, of the device,

Figure 3 is a sectional view taken on the line 33 of Figure 2,

' Figure 4 is a vertical sectional view showing the opening or socket formed by the reamer, I

Figure 5 is a vertical sectional view of a. crown 9 Claims. (CI. 32-59) 2 tooth and support therefor mounted on the root of the tooth,

Figure 6 is a bottom plan view of the crown stump base and support,

Figure 7 is a detailed side elevation of a modifled form of reamer,

Figure 8 is a detailed side elevation of another modification of this reamer,

Figure 9 is a detailed side elevation of a further modification of this reamer,

Figure 10 is a detailed side elevation of :a further modification of this invention.

Referring to the drawings and first to Figures 1 and 2, the numeral I ll designates generally a conical reamer shank which has secured to or formed integral with the upper large end thereof a cap H. The cap ll includes a downwardly extending annular flange 12 forming an annular chamber [3 between the flange l2 and the base or upper end of the reamer shank H1. The cap I I has extending laterally therefrom at the upper end thereof an annular flange M which forms a stop for limiting the insertion of the shank 10 within the canal of the tooth root. A stem l'5 extends upwardly from the cap H, being formed at its upper end with a coupling means I 6 of conventional construction, whereby th stem l5 may be detachably coupled to an engine hand piece. The outer surface of the reamer shank I0 is coated with an abrasive l1 and the under side of the cap I I is also coated with an abrasive l8. The three sides of the flange l2 are also coated with an abrasive 19 so that when the reamer shank l 0 is moved downwardly into the canal of the tooth root. a conical opening of uniform configuration will be formed and the three sides of the flange [2 which have an abrasive mounted thereon will form an annular groove 20 in the root 2|.

In order to provide for release of the material removed from the tooth by the abrasive, the cap I0 is formed'with an opening 22 which extends from the outer side of the cap and communicates with the chamber l3. The reamer is coupled to the engine hand piece in the normal manner and is then moved downwardly within the canal of the tooth root and thereby forms a conical socket 23 of uniform configuration. .The flange l2 forms the annular groove or channel 20 and also forms an annular rib 24 at the upper or base end of the socket 23. There is also formed a relatively large opening 25 above the rib 24 for receiving the base of the crown stump. As shown in Figure 5, the peg or root 26 of a crown tooth support is inserted in the conical socket 23 formed by the reamer being cemented therein and the peg or root 25 is formed at its upper end with a flanged cap or head 21 which snugly engages in the annular groove 20 and also fills the chamber 25. A crown stump 28 extends upwardly from the cap or head 2! and the crown tooth 29 is adapted to be formed about the stump 28. The lower end of the crown tooth 29 bears against the upper previously formed end 3!! of the tooth 2| and is cemented or otherwise firmly secured thereto.

Referring now to Figure '7, there is disclosed a modified form of reamer which includes a shank 3! of spiral configuration, and which has formed integral with the upper end thereof of cap- Ila having an annular flange lZa coated on the inner and outer sides, and the lower edge thereof, with a suitable abrasive. The cap lla has an annular flange I la extending laterally therefrom which forms a stop or limit means for limiting the extension of the reamer shank 3! into the canal of the tooth root. As shown in Figure 7, the upper side of the cap lid and the flange Ma is flat, whereas in Figure 8 there is disclosed a slightly modified form of this reamer wherein the upper side of the cap I lb and the flange Mb are of convex configuration.

Referring to Figure 9, there is disclosed a further modification of this reamer. In this form of the invention the upperportion of the reamer is identical with the reamer shown in Figures 1 and 2, with the following exceptions: the shank i li o, which is of tapering shape, is substantialiy shorter in length than theshank lo and is designed for small rooted teeth where the canals are small and it is hazardous to ream the roots large-enough all the .way down in making crown supports. The shank tile is coated with an abrasive lie for only a portion of the length thereof, from the upper large end, and abrasive covering not more than one-third of the length of the shank, and the remaining uncoated portion 32 of the shank constituting a tapering guide.

Referring. to Figure 10, there is disclosed a modification of the structure shown in Figure '7. The structure shown in Figure 1c is identical with that of Figure .7, with the exception that the spiral cutting portion. 33 which. extends from the upper end of the shank 3 5 extends downwardly from the upper end for a distance of about onethird of the length of the shank, and the remaining smooth lower portion 35 of the shank serves i as a guide for the tool without effecting any cutting or enlargement of the canal.

In the use of this reamer the tooth root H is cut oil, so as to provide a flat upper surface 30 whereupon the reamer such as the reamer shown in Figures 1 and 2, is inserted in the engine hand piece. The reamer shank i0 is then moved downwardly into the canal of the root 2i being moved downwardly to the limit provided by the stop flange i l. The material cut by the abrasive may be discharged from the canal through the passor if desired, the reamer may be periodicaily removed and cleaned in liquid or by any other suitable means. When the cap ll engages the upper end of. the tooth root 2i, the cutting flange it will form the annular groove to and the abrasive it on the lower side of the cap il will form. the rib 24 which is positioned below the upper surface 3% of the tooth root. The crownv tooth support including the. peg or root- 26 and. the. crown stump 22. may then be placed on the root 2i, the peg or root 26 being cemented or otherwise firmly secured in the socket. 23. The upper surface. of the head or cap 2'! at. the upper end of the peg orroot at will be ill " not be required to have any special training in t at the mounting of crown teeth and can readily prepare the tooth root for the crown tooth. This reamer may be used for teeth which are nonvital or teeth wherein the nerve is dead, which teeth are so often extracted because of the difficult procedures previously employed in restoring them.

Stump work forthe foundation of jacket crowns and pivots has been employed in dentistry for many years. hazardous and difficult procedure. The procedure in the old method was first to cut the crown of a deciduous or dead tooth oif to or below the gum-line, then to ream the root canal sufficiently large to insert a pin. The gum end or upper surface of the root was then countersunk or ground out near to the outside periphery of the root, a depth of several millimeters. The cavity or countersunk space was continuous with the enlarged root canal. The usual method of producing the countersunk space was to employ small freehand fissure burrs. A pin was then inserted into the enlarged root canal and wax waspressed over it filling the cavity. The wax with pin attached was then drawn out of the root, and by casting process metal replaced the wax making a union with the pin. The resulting part was then cemented into the root after the crown hadbeen attached to it in one of several ways.

In my method, as set forth in this application, there is a decided conservation of root structure with maximum strength. Another outstanding feature of my invention is that it provides a double support involving two principles, namely, the countersunk space and an annular trough. This recess,. which is continuous with the en larged root canal of definite size, provides for the insertion of a perfectly fitting metal cap attached to a pin. This ready made part obviates the casting process and the waxing step, thus saving at least seventy-five percent of time. This method has proven to be far less nerve rackin to the patient and dentist. As before stated, the entire operation is performed in one short sitting whereas it has taken three or more sittings with the oldv method accompanied by uncertain and hazardous results.

Tooth rootsare of different sizes and lengths, therefore, it would be impractical to give exact dimensions of the length and radius of my instrument which is employed in this invention, but in no case would it be necessary for the annular flange which creates the annular trough below the countersunk space to be deeper than three to four millimeters.

The exact configuration illustrated is regarded as the optimum, but some of the desirable results inherent in this disclosure may be obtained by various slight modifications including some departure from the exact configuration shown, and it is therefore requested that the scope of the Prior to this invention it was a invention should be regarded as limited only by the terms of the claims.

What I claim is:

1. A reamer for preparing a tooth root for re- CeiVing a crown tooth comprising tapered shank, a cap at the upper end of said shank including a depending annular flange, an abrasive on the lower inner side of said cap and about the inner and outer sides and lower edge of said flange, an outwardly extending annular flange carried by said cap constituting a stop, and a chuck engaging stem extending from the upper end of said cap.

2. A reamer as set forth in claim 1, wherein the outer surface of said shank is coated with an abrasive.

3. A reamer as set forth in claim 1 wherein the outer surface of said shank is formed with a spiral cutter.

4. A reamer as set forth in claim 1, wherein the upper surface of said second flange is coplanar with the upper flat surface of said cap.

5. A reamer as set forth in claim 1 wherein the upper surface of said second flange is convex.

6. A reamer as set forth in claim 1 wherein the tapered shank is coated with an abrasive about its upper third.

7. A reamer as set forth in claim 1 wherein the tapered shank is provided with a spiral metal cutter for a portion of the length thereof extending from the upper end thereof, the remaining lower portion of the shank being smooth and constituting a guide means.

8. A reamer as set forth in claim 1, wherein said abrasive extends downward from the upper end of said shank for a distance of substantially two millimeters from the lower edge of said cap.

9. A reamer as set forth in claim wherein said abrasive engages about only the lower portion of the outer side of said flange.

PHILLIPS BROOKS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,794,128 Walsh Feb. 24, 1921 2,250,058 Brooks July 22, 1941 

